Terminal assembly shield



April 6 M. R. ANDERSON 3,129,049

TERMINAL ASSEMBLY SHIELD Filed Dec. 5. 1960 Fig.2.

WITNESSES I INVENTOR yz $7M, Melvin R. Anderson.

4 TTORNEY 3,129,049 TERMINAL ASSEMBLY SHIELD Melvin R. Anderson, Avon Lake, Ohio, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Dec. 5, 1960, Ser. No. 73,5502 Claims. (Cl. 339-149) This invention generally relates to protective devices and more specifically relates to an electrical insulating shield for terminal assemblies.

Most sockets used in street lighting luminaires and similar equipment contain exposed line terminals. In some cases, these terminals may be continuously energized so as to be what is commonly termed hot terminals. An example of such continuously hot terminals would be those used in photo-electric control operation of street lighting luminaires. In such operation, if relamping or other maintenance work is performed on a street lighting head even during the daytime, the line terminal is still energized and will cause a severe electrical shock to the personnel who come in contact therewith.

To prevent such injuries, it has been common in the past to use a large mogul screw porcelain insulator which covers the entire socket. However, this item must be unscrewed and held separately to gain access to the socket terminals which results in an inconvenient and ineflicient protective device. Another attempted solution for this problem has been the use of small cup-like porcelain insulators which partially insulate the head of the terminal screws only. But this latter device is open on the top and the screwhead is disposed only A" below the top surface of the insulator, thereby rendering actual contact therewith stiil quite probable.

The present invention is directed to a shield that eliminates these disadvantages and provides an elficient, simply constructed, and relatively inexpensive device.

Accordingly, an object of this invention is to provide a simply constructed yet efficient shield for otherwise eX- posed terminal assemblies.

Another object of this invention is the provision of a novel and eliicient electrical insulating member.

Another object of this invention is to present a terminal shield which, for all practical purposes, eliminates the possibility of accidental contact with an energized terminal when maintenance work is performed on apparatus containing such terminals.

Still another object of this invention is to provide a terminal shield which can be readily installed or removed.

A further object of this invention is to provide a shield for terminal assemblies which not only substantially prevents accidental external contact with energized terminals by maintenance personnel, but which also permits immediate accessibility to the terminals whenever necessary.

A still further object of this invention is the provision of a uniquely shaped terminal shield made of a resilient insulating material so that portions thereof can be readily displaced by a screwdriver or the like when the screwdriver is to be used to manipulate the terminal screws or other fasteners employed therefor.

These and other objects, features and advantages of the invention will become more apparent upon consideration of the following detailed description of an illustrative embodiment thereof when taken in conjunction with the attached drawing, in which:

FIGURE 1 is a perspective View of a terminal shield constructed in accordance with the present invention;

PEG. 2 is a top plan view of a socket assembly including one of the terminal shields of the present invention;

FIG. 3 is a side elevational view of the socket assembly of FIG. 2 with a portion thereof being broken away;

FIG. 4 is a side eleavtional view of a terminal assembly United States Patent 0 and shield after a suitable manipulative tool, such as a screwdriver, has been inserted therethrough; and

FIG. 5 is a view similar to that of FIG. 4 only with the tool having been rotated from its position as shown in FIG. 4.

In accordance with the foregoing objects, there is here presented a one-piece terminal shield made of resilient insulating material which permits ready access to operating components of a terminal assembly enclosed by that shield while still substantially preventing accidental bod-- ily contact with the terminal. The terminal shield, in one application, is easily secured to the terminal assembly by the screw or other fastener used to secure the electric conductors to the assembly. In addition the shield can be manipulated by the tool employed for the screw or other fastener to gain access to the terminal assembly.

Referring more particularly to FIG. 1, it can readily be seen that the terminal shield Jill is of a generally A- shaped configuration, in this example, and comprises an upper section 12 and a lower section 14, which are separated from one another by a horizontal web 16. The shield 10 is shown installed on a socket assembly 18 in FIGS. 2 and 3. The socket assembly 13 comprises a .base 20 having an integrally formed stem portion 22 which supports the threaded socket 24. The apertures 26 form a means for receiving elements to secure the socket assembly 18 to apparatus such as streetlighting luminaires and the like. Extending outwardly from the sides of the socket assembly 18 are a pair of terminal assemblies 28 which provide the means for connecting the socket assembly 18 to leads from a power source (not shown) in order to energize the socket 24.

Screws 3i? of the terminal assembly 28 are threadedly engaged in an aperture in the top cross portion of bracket 32 so as to have an upward and downward movement therein so that by turning the screw 30 by means of a screwdriver 34 or the like, an electrical connector 40 can be engaged in space 36 between the bottom cross portion of the bracket 32 and plate 33 adjacent the bottom of the screw 30. In effect, however, the plate 38 is not secured to the bottom of the screw 30 but the plate 38 is slotted on each end thereof so as to be slidable within the confines of the bracket 32. The screw 30 when turned down merely engages the top of the bracket 38 so as to press it downwardly so that it in turn engages the electric connector 40.

Each terminal assembly 28 is secured to the socket as sembly 18 by means of an L-shaped arm 42 which has one leg thereof fixedly connected with the bracket 32 by mean of a recessed pin, or by welding and the like, and has another end thereof which is apertured for connection to the sockt 24 of the socket assembly 18 by means of screws 44. If desired, an additional aperture 46 can be provided in the corner of each arm 42 so that an additional terminal assembly (not shown) can be connected thereto if desired. This arm 42, in turn, engaged by an electrical contact 48 for engaging the terminal of a light source which is inserted into the socket 24. The screws 44 are conventional and are used to hold the relative parts of the socket assembly together.

. As can be readily seen, the lower section 14 of the terminal shield 10 is substantially of a channel shape or an inverted U-shape with an open bottom to fit over the top of the bracket 32 of the terminal assembly 28. The upper section 12 desirably is semi-circular in shape and has a longitudinal slit 50 through the top thereof. A hole or aperture 52 is pierced through the horizontal web section 16 to accommodate the screw 30. When the screw 30 is tightened, its head 31 secures the shield 10 to the bracket 32.

When thus secured, the side walls or legs 54 of the lower section 14 serve to cover the side portions of the bracket 32 of the terminal assembly 28 and the curved arms 56 of the upper section 12 serve to cover the head 31 of the screw 30. The walls 54 and arms 56 have a relative length sufficient to cover the entirety of the bracket 32. Preferably the length should be even slightly longer than the bracket 32 to provide a protective overlapping of the ends thereof. The terminal shield is desirably made of a flexible insulating material such as silicone rubber or its equivalent so that the arms 56 can be readily moved to separated positions when a tool 34 is inserted through the slit 50 to engage the screw 30. Thus the head of the assembly 28 is shielded, for all practical purposes, from accidental bodily contact by maintenance personnel but the screw 30 is readily accessible for manipulation through the slot 50 in the upper section 12. As illustrated clearly in FIGS. 4 and 5, once the point of the tool 34 has penetrated through the slit 50, it can be rotated as much as is necessary, due to the flexibility of the arms 56, without disturbing the protective effect of the terminal shield 10. Further, if any other objects such as a reflector or a tool, were accidentally laid across the top of a terminal shield 10, the arms 56 in the top section 12 would close around and over the screw 30 to insulate it from still further contact therewith.

If desired a recess 58 can be provided along each side of the slit 50 when the terminal shield is molded. This recess 58 can serve as a guide for insertion of the tool which cuts the slit 50 in the upper section 12, during fabrication of the insulator shield 10. Also, if desired, reinforcing ribs or ridges 6i and 61 can be formed on the walls 54 of the lower section 14 to not only give it added strength, as do the upper ridges 61 in particular due to their location with respect to the web 16, but to also provide a natural bending action for the walls 54 about the outer curved portion 62 thereof to prevent what otherwise might be a tearing action at the juncture of the Walls and the web 16. The lower ridges 60 further aid preventing the free ends of the legs 54 from curling up between the wall of the socket 24 and a side portion of the bracket 32 when the shield 10 is inserted into position around the terminal assembly 18, and from becoming ragged after a long period of use. The upper ridges 61 also serve to firm the legs 54 and arms 56 in their proper positions as shown in FIG. 1.

This invention, therefore, provides for a relatively inexpensive and simply constructed terminal shield made of a resilient insulating material which provides ready access to a terminal assembly when necessary without requiring additional diflicult manipulations.

Since it is obvious that the invention can be embodied in other forms and constructions within the spirit and scope of the present invention, as would be apparent to one skilled in the art, it is to be understood that the particular form shown is but one such embodiment. Accordingly, with various modifications and changes being possible, the invention is not limited in any way with respect thereto. Moreover, it is to be understood that certain features of this invention can be employed without a corresponding use of other features thereof.

What is claimed as new is:

1. A shield for an assembly having a terminal bracket and a terminal screw, said shield being of one-piece construction comprising a first means for shielding said bracket and a second flexible insulating means for shielding said screw, said first and second means including a common interconnecting web portion having an aperture of a size so that said screw can pass therethrough, and said second means including separable slot means for providing ready accessibility to said screw without impairing the protecting function of said shield.

2. A terminal assembly shield comprising a body portion having adjacent sections, one of said sections having generally parallel legs, the other of said sections having converging arms abutting one another and extending generally in a direction opposite from said legs, at

least the arms of said other section being flexible, an apertured web section joining the legs of said one section and the arms of said other section, said shield providing electrical insulation for said assembly while still permitting ready access to said terminal screw.

3. A terminal assembly shield comprising a body portion having adjacent sections, one of said sections having generally parallel legs, the other of said sections having separated and converging arms extending in a direction generally opposite from said legs, at least the arms of said other section being flexible, an apertured web section joining the legs of said one section and the arms of said other section, rib means formed on the outside surfaces of said legs generally at their extremities providing reinforcement thereof and a natural bending point intermediate the ribs on each leg, said shield providing electrical insulation for said assembly while still permitting ready access to said terminal screw.

4. A terminal assembly shield comprising an insulator body portion having adjacent sections, one of said sections having generally parallel legs, the other of said sections having converging arms, said legs and said arms being flexible and, a common web section joining said legs and said arms, ridge means formed on the outside surface of said shield generally at each juncture of said legs, arms, and web for reinforcing said juncture so as to prevent tearing of the shield thereat and to firm said legs and arms in their aforementioned positions.

5. A terminal assembly shield comprising interconnected adjacent sections of insulating material, one of said sections for enclosing a terminal screw head and the other of said sections for enclosing a terminal bracket, said one section having a pair of curved leg portions which substantially meet at their free ends to present a generally semi-circular configuration, said leg portions being resilient and separable from one another, said other section being generally channel-shaped having arm portions extending in a direction generally opposite from that of said leg portions and a web interconnecting portion, said web portion including means for readily engaging said shield with a terminal assembly.

6. An electrically insulated terminal assembly including a generally rectangularly shaped terminal bracket, a headed terminal screw engaged in one side of said bracket, a generally A-shaped resilient insulating shield, said shield including an aperture in its web portion of a suflicient size to permit all but the head of said screw to pass through, said screw engaged through said aperture and the head thereof securing said shield to said bracket, the bottom open end of said shield overlapping said one side of the bracket and extending downwardly along two other sides of saidbracket, and said shield including a slit generally across the apex portion thereof, said shield permitting ready access to said screw but substantially preventing accidental contact of objects with said assembly.

7. An electrically insulated terminal assembly including a generally rectangularly shaped terminal bracket mounted closely adjacent a socket, a headed terminal screw engaged in one side of said bracket, a generally A- shaped resilient insulating shield, ridge means formed on the outside surfaces of said shield generally adjacent the juncture of the web and sides of said shield for strengthening said juncture, enlarged portions on the free ends of said shield to prevent curling up of said ends when said shield is placed on said terminal and is engaged generally between said terminal and said socket, saidrshield including an aperture in its web portion, said screw having the shank thereof'en-gaged through said aperture and the head thereof securing said shield to said bracket, the bottom open end of said shield overlapping said one side of the bracket and extending downwardly along two other sides of said bracket, and said shield including a slit generally across the apex portion thereof, said shield permitting ready access to said screw but substantially preventing accidental contact of objects with said assembly.

8. A terminal assembly shield comprising a body portion having adjoined sections, one of said sections being of a generally inverted U-shaped configuration and the other of said sections being of a generally inverted U- shaped configuration, said one section being formed of flexible insulating material and having a slit in the bight portion thereof, said shield providing electrical insulation for said assembly While still permitting immediate access thereto by a tool through sad slit when desired.

9. The combination comprising a terminal assembly and an insulating shield, said assembly having at least a pair of parallel side portions joined by a cross portion, said shield comprising a body portion having adjacent sections, one of said sections having generally parallel legs juxtaposed with said side portions and generally coextending therewith, the other of said sections having separated but converging flexible arms extending generally over said cross portion and in a direction generally opposite from said legs, a common Web section joining said legs and said arms, said shield providing electrical insulation for said assembly While still permitting ready access thereto.

10. The combination comprising a terminal assembly and an insulating shield, said assembly having at least a pair of parallel side portions joined by a cross portion, said shield comprising a body portion having adjacent sections, one of said sections having generally parallel flexible legs juxtaposed with said side portions and generally coextending therewith, the other of said sections having separated but converging flexible arms extending generally over said cross portion and in a direction generally opposite from said legs, a common web section joining said legs and said arms, rib means formed on the outside surfaces of said legs generally at their extremities providing reinforcement thereof and a natural bending point intermediate the ribs on each leg, said shield providing electrical insulation for said assembly while still permitting ready access thereto.

References Cited in the file of this patent UNITED STATES PATENTS 2,229,849 Heidebrecht Jan. 28, 1941 2,701,273 Badeau Feb. 1, 1955 2,707,774 Keller May 3, 1955 2,715,664 Lucas Aug. 16, 1955 2,740,001 Vergilio et a1. Mar. 27, 1956 2,862,997 Veitch et a1. Dec. 2, 1958 FOREIGN PATENTS 537,190 Canada Feb. 12, 1957 

1. A SHIELD FOR AN ASSEMBLY HAVING A TERMINAL BRACKET AND A TERMINAL SCREW, SAID SHIELD BEING ONE-PIECE CONSTRUCTION COMPRISING A FIRST MEANS FOR SHIELDING SAID BRACKET AND A SECOND FLEXIBLE INSULTING MEANS FOR SHIELDING SAID SCREW, SAID FIRST AND SECOND MEANS INCLUDING A COMMON INTERCONNECTING WEB PORTION HAVING AN APERTURE 